Sherardizing furnace



A. M. MAcFARL AND.

SHERARDIZ ING FURNACE. APPLICATION F ltED AUGIEI 19 21.

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Patented Oct. 31, 1922.

INVENTOR A///'s /7./7acfZ7r/0/7d A'TTORNEY Pasta 0a. 31, 1922.

ALLIS H; mm, 0]? PITTSBURGH,

1,433,135 OFFICE.

YEN'NSY'LVANIA, ASSIGNOB TO WESTING- HOUSE m0 AND mun-ammo COIPANY, A CORPORATION OF PENN- SYLVAH'IA.

SHEBABZDIZIN G FURNACE.

Application filed August 15, 1911. Serial ll'o. 493,331.

To all whomz't may concern:

Be 'it known that I, Anus M. MACFAR- LAND, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Sherardizing F urnaces, of which the followin a specification.

y invention relates to electric furnaces and particularly to electrically heated sherardizing furnaces, and it has for its object to provide a relatively small and compact electrically heated sherardizing furnace which will permit of practically uninterrupted operation.

I am aware of sherardizing furnaces in which chambers for the materials to be treated are non-removable. In such furnaces, removal of the treated material from, and the refilling of, the chambers may re quire considerable time and, consequently, the furnaces are not in operation for as large percentage of the total time as would be the case if the chambers were removable.

In practising my invention, I provide a tiltable double-wall heat-insulating tubular casing having one removable end closure and containing a plurality of longitudinally extending members of channel section to receive and support the heating elements. A quickly removable drum is located in the casing and is supported in bearings in the easing ends to be rotated by suitable means. One end of the drum is provided with a removable closure having means to facilitate lifting the drum out of, and lowering it into, the casing.

In the single sheet of drawings,

Figure 1 is a view, in vertical longitudinal section, of a furnace embodying my invention, and

Flg. 2 is a view in lateral vertical section. on the line II-II of Fig. 1.

A tiltable double-wall casing 3 comprises an outer sheet-metal cylinder 4 of substantially tubular form and an inner sheet-metal cylinder 5 also of substantially tubular form and of materially less diameter than the outer member 4. A mass 6 of suitable heat-insulating material may be located be tween the two cylinders 4 and 5. The ends of the c linder 5 are provided with annular flanges I which permit of locating the cylinders 4 and 5 in fixed operative positions relatively to each other.

One end of the casing 3 is provided with a non-removable closure comprising an outer sheet-metal disk 8 which may be bolted to one of the flanges 7 by a plurality of bolts 9. A mas of heat-insulating material 10 is located adjacent to the inner surface of the disk 8. A relatively heavy metal disk 11 is located in engagement with the inner surface of the mass of heat-insulating material '10 and may be provided with an annular extension 12 to permit of suitably securing the disk to the cylinder 5. At substantially the center of the disk 11, is a bearing member 13 which, as illustrated in Fig. 1, may be a tube of any suitable metal.

The other end of the casing 3 is a quickly removable closure 14 comprising an outer sheet-metal disk 15 and a relatively heavy inner metal disk 16 spaced therefrom to receive a mass 17 of suitable heat-insulating material. The disk 15 may be secured to the disk 16 by any suitable or desired means. A plurality of resilient members 18 are pivotally mounted on the casing 3 to clamp the closure 14 in position.

A pair of relatively short shafts 19 and 20 are mounted in diametrically opposed relation on the outside of the casing 3 at'substantially the middle of its length. A supporting frame comprises two members 21 substantially of A form which are provided, at their upper ends, with suitable bearings 22 for the shafts 19 and 20, thus permitting of tilting the casing 3, whenever desired, by means of a hand Wheel 23 suitably secured to the shaft 20. It is to be understood that the above-described construction of supporting means for the casing 3 is illustrative only and that any other suitable or desired construction of bearings and supporting members, which will permit of tilting the casing, may be employed.

A plurality of members 2 of channel section are suitably secured to the inside surface of the inner cylinder 5. Suitable resistor members 25, only one of which is illustrated in the drawings, are located in the channel members 24 and may be of any suitable or desired construction usually em ployed for such purposes.

A drum 26 is located inside the casing 3 and comprises a sheet-metal cylinder 27 having a non-removable head 28 secured to one of its ends. The head 28 is provided with a shaft 29 to co-operate with the bearing memher 13 to maintain the drum 26 in its operative position within the casing 3. The other end of the drum 26 is closed by a'removable head 30 which may be secured to the drum by a pluralityof studs 31 and nuts 32 and which is of larger diameter than the drum itself. The head 30 is provided with an integral axial projection 33 to fit into a bearing block 34 which is secured to the inner surface of the end 14. A hole 35 is provided in the projection 33 to receive a suitable implement for lifting the drum out of the casing 3 whenthe same has been tilted to substantially the 1iposltion illustrated by the broken lines in ig. l and the end 14 has been removed.

Means for rotating the drum 26 within the casing 3 comprisev a shaft 36,. a worm 37 thereon, a worm wheel 38 and a friction pulley 39 suitably secured to the worm wheel 38, the members 38 and 39 being rotatably mounted on a short shaft 40 which, in turn, is mounted on a suitable supporting member 41 only a portion of which is illustrated in' Fig. 1. r

A portion of the casing 3 near one end is cut away to form an opening 42 into which the worm wheel 38 and the friction pulley 39 may project to engage the outer pe riphery of the head 30 to rotate the same and the drum 26 when the shaft 36 is rotated by an suitable means (not shown).

erminals 43 of the resistormembers 25 may extend through an insulating tube 44 located within the shaft 19, suitable means for the control of the heating elements (not illustrated) being provided.

A plurality of furnaces of the hereinbefore-described character may be installed in any room or space and operated substantially without interruption by providing suitable means, such as an overhead track or trolley, for handling the drums substantially as will now be described. One of the drums 26 may be filled with the material to be heat-treated and may then be brou ht to one of the hereinbefore-described urnaces from which the end 14 has been removed and which has been so tilted that it occupies substantially the position illustrated by the broken lines in Fig. 1. The drum 26 may then be lowered into the casing 3, the construction of the bearing member 13 and of the channel members 24 being such that the shaft 29 will easily enter the bearing member 13. All of the weight of the drum 26 is sustained by the lower end of the casing, the disk 11 being made of sufficient strength for this purpose. The closure 14 may now be put in place and the resilient clamping members 18 applied to hold it securely in place. The construction of the projection 33 and of the bearing block 34 is such that the placing of the closure 14, as hereinbefore described, against the the articles have been treated, the heating elements 25 may be temporarily de-energized, the casing 3 tilted upwardly and the closure 14 removed, after which the drum 26 so may be removed and another drum, filled with articles to be heat-treated, may be quickly placed in the casing which may be again tilted downwardly and placed in operation.

It may be noted that the furnace embodying my invention is relatively small and compact and may be used effectively for heat-treating metal articles by means of substantially stationary electrical heating means. It may further be noted that the furnace embodying my invention comprises a tiltable furnace casing and a readily removable drum for articles which have been, or are to be, subjected to heat treatment.

Various modifications may be made in the device embodying my invention .with out departing from the spirit and scope thereof, and I desire that only such limitations shall be placed thereon as are imposed 100 by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

1. An electrically-heated device comprising a tiltable double-wall heat-insulated tubular casing, a closure for one end thereof secured to said casing, a quickly removable closure for theother end of said casing, a rotatable drum in said casing, a bearing member in each of said closures for rotatably supporting said drum and a heating element inside of said casing for heating said drum.

2. An electrically-heated sherardizing furnace having an unloading and loading position and an operating position, comprising a tubular tiltable casing, means for mor ing said casing from the one to the other of its positions, a resistor located adjacent the inner surface of said tubular casing, a rotatable drum in said casing, closures for the ends of said casing, bearing member; in said closures for said drum and means for rotating said drum when the casing is in its operating osition.

3. An electrically heated furnace comprising an outer metallic tubular member, an inner metallic tubular member spaced from the outer tubular member, heat-insulating material between said members, a plurality of longitudinally-extending members of channel shape located on the inside of said inner tubular member, electric heating elements located in said channel members, and a removable drum rotatably mounted inside of said tubular membersand adapted to be /heated by said heating element.

4.. An electrically-heated furnace comprising a tiltable double-Wall tubular casing, a

plurality of longitudinally extending members of channel section located inside of said casing, electric heating elements located in said channel members, closures for said-- tubular casing, one of said closures bein quickly removable, bearing members in said closures, a drum within said casing rotatably mounted in said bearings and means for rotating said drum.

5. An electrically-heated furnace comprisin a tiltable casing, closures for the ends or said casing, a drum rotatable in said casing, bearin members for permitting the rotation 0% said drum in said casing and for maintaining said drum in its proper positlon 1n sai casing while the casing is being tilted.

6. An electricall -heated furnace compr sing a tiltable dou le-wall tubular casing, a closure for one end of said casing, a bearing member therein, a quickly removable closure for the other end of said casing, a bearing member therein, a drum, having an open end in said casing and having a projection on its closed end for operatively engaging the bearing member in said firstmentioned closure, a removable cover member for the open end'of said drum and a projection on said drum cover member for permitting the lifting of said drum and for operatively en aging the bearing member in said remova 1e drum cover member.

In testimony whereof, I have hereunto subscribed my name this 28th day of July 1921.

ALLIS M. MAGFARLAND. 

